An electronic component mounting system that manufactures a mounted substrate by mounting electronic components on a substrate is constructed by joining a plurality of component mounting apparatuses which subject a substrate printed with solder bonding paste to various operations pertinent to component mounting, such as operations of mounting and inspecting components. An apparatus known as a component mounting apparatus of the kind has two substrate conveyance mechanisms and two operation performance mechanisms which individually correspond to the respective substrate conveyance mechanisms. Adopting such a configuration makes it possible to select one as a production mode from a so-called independent operation mode of letting each of two operation performance mechanisms perform a operation for a substrate held by one corresponding substrate conveyance mechanism and a so-called alternate operation mode letting the two operation performance mechanisms alternately perform respective operations targeted for both substrates held by the two substrate conveyance mechanisms (see; for instance, Patent Document 1). According to the related art described in connection with the patent document, a determination is automatically made on the basis of mount information about a substrate and components as to which one of the production modes is suitable for the substrate during a component mounting operation for mounting electronic components on substrates.